After adding a verifier to test all strings printed in trace events
to make sure they either point to a string on the ring buffer,
or to read only core kernel memory, it triggered on a workqueue
trace event. The trace event workqueue_queue_work references
the allocated name of the workqueue in the output. If the workqueue
is freed before the trace is read, then the trace will dereference
freed memory. Update the trace event to use the __string(), __assign_str(),
and __get_str() helpers to handle such cases.
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Merge tag 'trace-v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull workqueue tracing fix from Steven Rostedt:
"Fix workqueue trace event unsafe string reference
After adding a verifier to test all strings printed in trace events to
make sure they either point to a string on the ring buffer, or to read
only core kernel memory, it triggered on a workqueue trace event. The
trace event workqueue_queue_work references the allocated name of the
workqueue in the output. If the workqueue is freed before the trace is
read, then the trace will dereference freed memory.
Update the trace event to use the __string(), __assign_str(), and
__get_str() helpers to handle such cases"
* tag 'trace-v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
workqueue/tracing: Copy workqueue name to buffer in trace event
278924cb99